Malicious PDF — malware analysis report

Static analysis result for SHA-256 c1938afdef821caa…

MALICIOUS

PDF

80.2 KB Created: 2021-09-02 09:09:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 06b45624cc58ba6fde3b610b476643a3 SHA-1: 6b7924b2b0e2789ef8f4eb768f27cd5d84fa29cc SHA-256: c1938afdef821caa9e81ec962ed2eba4c28965b8968ea94f653cbb99af1817dc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It contains numerous links to external websites, many of which are hosted on compromised CMS platforms, suggesting a link farm or phishing lure. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics indicates an attempt to distribute malicious content or phish users through these compromised sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://medvor.ru/uplcv?utm_term=is+geothermal+a+nonrenewable+resource PDF link annotation
    • https://tempegaring.com/contents//files/9602078449.pdfIn PDF document text
    • https://kantankacreative.com/wp-content/plugins/super-forms/uploads/php/files/d55c88461415812d61f51592d7a5e858/40120769174.pdfIn PDF document text
    • https://anctools.com/ckfinder/userfiles/files/29664493029.pdfIn PDF document text
    • http://renovator.cz/files/file/48563087095.pdfIn PDF document text
    • http://www.cavice.fi/tiedostot/files/62081544878.pdfIn PDF document text
    • http://rosniyom.com/userfiles/files/89363268944.pdfIn PDF document text
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8297ec037---28786463447.pdfIn PDF document text
    • http://interface-referencement.com/userfiles/file/32814722474.pdfIn PDF document text
    • https://ateneoarbonaida.com/wp-content/plugins/formcraft/file-upload/server/content/files/160974661f352f---gijesamejefuxuzavoxol.pdfIn PDF document text
    • http://nachhilfeschule.havonix.com/ckfinder/userfiles/files/52092985304.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/bq3388907s2kumshu193ui4e04/44662531501.pdfIn PDF document text
    • https://www.keystonecare.co.uk/wp-content/plugins/super-forms/uploads/php/files/faffe03c3d8b73db83a48f1763dfbbcf/92418977584.pdfIn PDF document text
    • https://juvelyrikoscentras.lt/Files/file/67135703684.pdfIn PDF document text
    • https://hoovermaids.com/wp-content/plugins/super-forms/uploads/php/files/e2a628b4f52812cbe191c10d2fe617ae/wepejusi.pdfIn PDF document text
    • http://dent-pro.cz/pic/file/14817737523.pdfIn PDF document text
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611d5b842e73e---xowibixedewakipa.pdfIn PDF document text
    • http://bulmarconsult.com/files/90683206590.pdfIn PDF document text
    • https://wittnebel.dk/file/menedomotexal.pdfIn PDF document text
    • http://call.ae/wp-content/plugins/formcraft/file-upload/server/content/files/16075026830cfe---motes.pdfIn PDF document text
    • http://mustang.tom.ru/jsplugins/ckfinder/userfiles/files/fujeru.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d468.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD468 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ec7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC7F 10864 bytes
SHA-256: f4217c8a9cba725d37537609bd2168aa8424339b88c934631372c923c64b6376
font_02_sfnt_off0001057e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1057E 17528 bytes
SHA-256: 798945596c7e284ac0d91ab90f62a83250614a31a3f00d25a5a2a6dc470b92b8